Improvement in hydraulic air-compressers



W. E. 'PRALL. Improvement in Hydraulic Air Compressor.

Patented Nov. 7,1871'.

In m n/toreem wfieek w W W UNITED STATES PATENT .OFFICE.

WILLIAM E. PRALL, OF WASHlNGTON, DISTRICT OF COLUMBIA.

IMPROVEMENT lN HYDRAULIC AIR-COMPRESSERS.

Specification forming part of Letters Patent No. 120,597, dated November 7, 1871.

To all whom it may concern:

'Be it known that 1, WILLIAM E. PRALL, of Washington, District of Columbia, have invented certain Improvements in Hydro-Pneumatic Engines, of which the following is a specification The obj eat of this invention is the construction of an automatic device for compressing air, for mechanical and other purposes, by means of the direct pressure of water against the air and it is designed to be used in such places where the natural fall of water would be sufficient to com municate the required pressure. The important features of this invention consist in the arrangement of the water-supply and discharge-pipes, the air-supply and discharge-pipes, and the automatic operation of the valves in such a manner as to almost entirely dispense with the friction and loss of power which result from the use of piston-pumps for the purpose, and reducing very much the cost in the construction as well as repairs of such machinery.

The construction of this machine is as follows, Figure 1 being a partly-sectional view:

a is an iron cylinder, of such capacity and strength as may be required, placed at such a distance from the water-source as will permit the discharge-water to flow away from the machine. b is a water-pipe extending from the reservoir to the cylinder a, and entering the same near the bottom. 0 is a discharge-pipe for the water in cylinder a. cl is an air-pipe extending from the top of cylinder a, and is used to conduct the compressed air to the point where it is to be used. 6 is a pipe entering the cylinder to at the top, and is provided with a check-valve, j, which opens inward so as to permit the air to flow into cylinder to while the water is running out. f is a balance-valve placed in pipe I). g is also a balancevalve placed in pipe 0, these two valves being connected by means of a rod to the diaphragm h, which is placed in such a position as to communicate a motion to both valves by the same movement. It is a check-valve placed in the pipe, which connects the upper side of the diaphragm h with the cylinder at. Z and m are small pipes extending from near the bottom of cylinder 00 to the water-tank p. a is a pipe extending from near the top of cylinder a, and connecting with the upper side of the diaphragm-case. 0 is a pipe extending from the water-tank, and connecting with the lower side of the diaphragmcase. r is a pipe connecting water-tank p with the air-pipe below the valve 11. s is a valve in pipe 1", opening upward. 1

The operation is as follows: The water-tank p is filled through an opening at the top; the water will run down pipe 0 under the lower side of the diaphragm and force it up, and as the rod which connects the balance-valves f and g is attached to it by means of washers on each side they will be carried up with it. The valve f is so arranged that the upward movement opens it, and the valves 9 placed so as to close by the upward movement. The diaphragm has twice the movement that is required to open either of them, and the plunger of each has an additional movement, after it has closed the part. The object of this is that the first half movement of the diaphragm upward will close the port or opening of valve 9 in the discharge-pipe, and, by the additional movement, open the port in valve f in the supply-pipe. The water from the source or reservoir will, as soon as valve f is opened, rush in and fill the cylinder a, expelling the air therefi'om through pipe at and valve 1'. As soon as the water has reached the mouth of pipe at, which enters the cylinder a at the top, the water, which has been prevented from rising in it by valve k at the bottom, will now rush down and fill it, the effect of which will be to equalize the pressure on both sides of the diaphragm. This done, the valves f and y will, by their own weight, drop down, the first half movement of which will shut the port of valve f and the last half open the valve g. This movement will permit the water to run out of cylinder at through pipe 0. The valve j in air-pipe 6 will open and permit air to take the place of the receding water. As soon as the water has run out below pipe 1 air will pass up that pipe, and the water will run down pipe m. The removing of the water from these pipes, which balanced the Water in pipe 0, will cause the water to descend from tank and. raise the diaphragm, and the operation is as before. There is no danger from overheating in the apparatus, as the heat is carried off by the Water.

I do not confine myself to any particular arran gement or position of the pipes and diaphragm, as it is plain that different arrangements of them would produce the same result.

The merit consists in so placing the pipes that the water will be withdrawn from one pipe so as to permit the other column to rest with its force on the diaphragm. It is the disturbance of the equilibrium that furnishes the power to operate the mechanism. The arrangement of a float is contemplated to perform the same function.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is 1. An air-compressing machine, consisting of the cylinder a, in which air is compressed by direct application of Water from an elevation and the Water-supply pipe b, Water-discharge pipe 0,

and air-supply pipe 6, airdischarge pipe 01, and valves f, g, 0;, and j, operating substantially as shown and described.

2. The cut-0E valves f g placed in the outlet and inlet-pipes b 0, and operated automatically by the force of the water as it passes through the machine, substantially as set forth.

W. E. PRALL.

Witnesses:

EDM. F. BROWN, JNo. D. DEFREES. 

